1. Field of the Invention
The present invention relates to an image-reading apparatus, an image-processing method, and a computer program product.
2. Description of the Related Art
Technologies have hitherto been disclosed for detecting a document position from a read image.
A known image-reading apparatus detects edges from the top and bottom and right and left of a read image and calculates linearity of the edges to determine a document position (See JP-A-2007-88654).
A known image-processing apparatus detects all edges in an image and calculates linearity from the edges to detect likelihood of a rectangle (See JP-A-2013-106160).
Another known image-processing apparatus performs horizontal and vertical scanning for the entire image and, through edge tracing or labeling, discriminates a plurality of document regions (See JP-A-2002-10059).
In the known image-processing apparatuses (e.g., JP-A-2007-88654), however, a greater reading length (image length) theoretically requires a large amount of memory, which leads to a problem of an increased amount of calculation.